It takes a URL or a paste, and the paste is the one to use when the writing is already yours. Several hundred words up to a few thousand works; below that there is nothing to choose between.
You get a mapping screen: each slide, the line it came from, and the words struck through where it cut. Nothing is hidden behind a "generate" button — the trade is visible before you accept it.
Some sentences cannot be shortened without changing what they claim. A list of four names cut after the second is a different sentence, not a shorter one. Where that happens the row says so instead of presenting a tidy label, and you cut it yourself.
Every slide is editable before you generate. The cuts are a proposal, not a verdict, and the original text stays beside them so you can see what was there.
It becomes a normal carousel in your brand kit — same templates, same designs, same exports. From there it is a post like any other, and it can go out as a video too.
The rule that makes this safe to use on your own writing.
Not paraphrased, not "tightened", not put in another voice. If a line will not fit, words come out — and the ones that came out are shown. Your sentence is still your sentence.
Cutting "Monday, Tuesday, Wednesday and Friday" after the second item is shorter and false. It never breaks a comma list, and where nothing can come out safely it says so rather than quietly changing your claim.
That is what a slide holds at a readable size — not a limit we invented but what the renderer can set without shrinking the type to nothing. Ten slides maximum, so a long article becomes a post, not a book.
One was rewritten to fit. One had words removed and shows you which.
It fits, and it sounds like a different company wrote it.
Same length on the slide. You can see precisely what it took.